CN115291378A - Optical path system of microscope - Google Patents

Abstract

The present disclosure describes an optical path system of a microscope, including an illumination module, a light splitting module, a scanning module, and an imaging module. The lighting module includes a first polarizing unit and a light source; the light splitting module is configured to receive a reflected light beam from the scanning module and convert the reflected light beam reflected to the imaging module; the scanning module is configured to receive the illuminating beam and emit the illuminating beam to the object to be tested and receive the reflected beam from the object to be tested and emit the reflected beam to the spectroscopic module, and the scanning module includes sequentially arranged along the propagation direction of the illuminating beam a turntable with a light-transmitting hole, a second polarizing unit, and a microscope objective lens; the imaging module includes a sensing unit and a third polarizing unit, the sensing unit is configured to receive the reflected light beam passing through the third polarizing unit, and the first polarizing unit The polarization direction of , and the polarization direction of the third polarization unit are different. According to the present disclosure, it is possible to provide an optical path system capable of reducing stray light in an optical path to improve measurement accuracy of an object to be measured.

Description

Microscope optical system

technical field

The present disclosure relates to an intelligent manufacturing equipment industry, in particular to an optical path system of a microscope.

Background technique

At present, optical microscopy technology is widely used in various fields of scientific and technological research, but ordinary optical microscopy technology cannot reconstruct the three-dimensional shape of objects with a certain thickness. With the continuous development of microscopic technology in recent years, confocal microscopic technology has become one of the important technologies in the field of optical microscopy. It has the characteristics of high precision, high resolution, non-contact and unique axial tomographic scanning imaging. Realize the three-dimensional shape reconstruction of the object to be tested, and have been widely used in the fields of micro-nano detection, precision measurement and life science research.

The traditional confocal microscopy detection technology is based on the principle of three-point conjugate of the light source, the object to be illuminated and the detector to perform single-point mechanical scanning, so the scanning speed is relatively slow, the mechanical control system is complicated, and the vibration caused by scanning is limited. It is not easy to realize real-time and fast three-dimensional measurement. In order to solve the disadvantages of slow imaging speed and small field of view of traditional confocal microscopy, parallel scanning confocal microscopy has emerged. The parallel scanning confocal microscopy technology improves the measurement speed of the original single-point confocal measurement, and the parallel scanning confocal microscopy detection technology based on the Nipkow disk (Nipkow disk) is simple in structure, easy to implement, Advantages of low cost and high image quality.

However, the introduction of the Nipkow turntable also causes more stray light to be generated by the confocal optical system, which leads to poor reconstruction of the three-dimensional shape of the object to be measured. Therefore, there is a need for a solution capable of reducing the stray astigmatism of the optical system to improve the accuracy of the three-dimensional shape reconstruction of the object to be measured.

Contents of the invention

The present disclosure is proposed in view of the above-mentioned state of the prior art, and its purpose is to provide an optical path system that can reduce stray light in the optical path to improve the measurement accuracy of the object to be measured and thus improve the reconstruction accuracy of the object to be measured.

The present disclosure provides an optical path system of a microscope, the optical path system includes an illumination module, a spectroscopic module, a scanning module, and an imaging module, the illuminating module includes a first polarization unit and a light source for emitting an illumination beam; the spectroscopic module It is arranged between the illumination module and the scanning module and is configured to receive the reflected light beam from the scanning module and reflect the reflected light beam to the imaging module; the scanning module is configured to receive light passing through the spectroscopic module and emit the illumination beam to the object under test and receive the reflected beam from the object to be measured and emit the reflected beam to the spectroscopic module, the scanning module includes sequentially arranged along the propagation direction of the illumination beam The turntable of the light transmission hole, the second polarizing unit, and the microscope objective lens; the imaging module includes a sensing unit, a third polarizing unit arranged between the sensing unit and the light splitting module, and the sensing unit configured to receive the reflected light beam passing through the third polarization unit, the polarization direction of the first polarization unit is different from the polarization direction of the third polarization unit.

In the present disclosure, by setting the first polarizing unit in the illumination module, and setting the third polarizing unit with a different polarization direction from the first polarizing unit in the imaging module, the illuminating beam reflected by the turntable is blocked and cannot enter the transmission. sensory unit. In this case, it is possible to reduce the possibility that the reflected light beam reflected by the non-test object enters the imaging module and is received by the sensing unit, thus, the signal-to-noise ratio of the reflected light beam from the test object can be improved to improve the imaging quality, Furthermore, the reconstruction accuracy of the object to be measured can be improved.

In addition, in the optical path system involved in the present invention, optionally, the illumination module further includes a first reflection unit for reflecting the illumination beam to the light splitting module, and the first polarization unit is arranged on the light source and the first reflection unit. In this case, the illuminating beam emitted by the light source can pass through the first polarization unit and reach the first reflection unit to be reflected by the first reflection unit to the spectroscopic module, thereby reducing the space ratio of the optical path system to improve The degree of integration of the optical system.

In addition, in the optical path system of the present invention, optionally, the lighting module further includes a first lens unit and a second lens unit arranged between the light source and the first reflection unit, and the first lens unit A lens unit is configured to collimate the illumination beam, and the second lens unit is configured to adjust the collimated illumination beam so that the position of the image of the light source is located on the rear focal plane of the microscope objective lens. In this case, the illumination beam can become parallel light after passing through the first lens unit, and the light source can be regarded as located at the entrance pupil of the microscope objective lens, so that the illumination beam can uniformly irradiate the surface of the object to be measured.

In addition, in the optical system of the present invention, optionally, the polarization direction of the first polarization unit is orthogonal to the polarization direction of the third polarization unit. In this case, even if the illuminating light beam (second stray light beam) reflected by the turntable is reflected to the imaging module through the spectroscopic module, the second stray light beam cannot pass through the third polarization unit and then reach the sensing unit, in other words, The setting of the third polarization unit can reduce the possibility that the sensing unit receives the reflected light beam (that is, stray light) that is not reflected by the object to be measured, thus, the measurement accuracy of the optical path system can be improved to more accurately measure the object to be measured. reconstruction.

In addition, in the optical path system involved in the present invention, optionally, the second polarization unit is a 1/4 wave plate. In this case, the illumination beam and the reflection beam pass through the 1/4 wave plate successively, which can rotate the reflection beam emitted from the scanning module by 90° relative to the polarization direction of the illumination beam, so that the reflection beam on the surface of the object to be measured can be transmitted After passing through the third polarization unit, it is received by the sensing unit.

In addition, in the optical path system involved in the present invention, optionally, a driving module having a first driving mechanism is also included, and the first driving mechanism is configured to drive the microscope objective lens to move in a preset direction so that the The area to be measured of the object to be measured is located at the focal plane of the microscope objective lens. In this case, by adjusting the position of the microscopic objective lens in the preset direction, the area to be measured of the object to be measured can be located at the focal plane of the microscopic objective lens, so that the reflected light beam reflected by the area to be measured can be focused on the transparent light hole.

In addition, in the optical path system of the present invention, optionally, the central axis of the turntable and the preset direction have a first preset angle greater than 0°. In this case, the illumination beam can also enter the scanning module through the light hole, and when the illumination beam is reflected by the turntable to form a second stray beam, the propagation direction of the second stray beam can propagate away from the imaging module , which can reduce the possibility that the second stray light beam enters the imaging module and affects the imaging of the object under test.

In addition, in the optical path system involved in the present invention, optionally, the scanning module further includes a tube lens disposed between the turntable and the microscope objective lens, and the tube lens is configured to adjust the illumination beam The image of the light source is located on the rear focal plane of the microscope objective lens, and the reflected light beam is adjusted so that the reflected light beam is focused on the light transmission hole. In this case, the reflected light beam reflected by the area to be measured on the focal plane can exit from the scanning module and reach the imaging module, thereby enhancing the signal-to-noise ratio of the imaging image to improve the measurement accuracy of the object to be measured.

In addition, in the optical path system involved in the present invention, optionally, it also includes an auxiliary light absorption module for absorbing the first stray light beam. the light beam on the inner wall of the inner wall, the auxiliary light-absorbing module includes a fourth polarizing unit arranged on the inner wall in a manner of inclining a second preset angle relative to the optical axis, a second reflecting unit, and a second reflecting unit arranged on the inner wall and located at the light-absorbing paper outside the field of view of the sensing unit, the fourth polarizing unit is configured to absorb the first stray beam from the spectroscopic module and reflect the first stray beam to the second reflecting unit, the The second reflecting unit is configured to receive the first stray beam from the fourth polarizing unit and reflect the first stray beam to the light-absorbing paper. In this case, the first stray light beam in the optical path system can be reduced to facilitate the subsequent improvement of the imaging quality of the object to be measured.

In addition, in the optical system of the present invention, optionally, the polarization direction of the fourth polarization unit is the same as that of the third polarization unit. Therefore, the fourth polarization unit can absorb the first stray light beam to reduce the stray light in the optical path system, which facilitates subsequent improvement of the imaging quality of the object to be measured.

According to the present disclosure, it is possible to provide an optical path system capable of reducing stray light in the optical path to improve the measurement accuracy of the object to be measured and thereby improve the reconstruction accuracy of the object to be detected.

Description of drawings

The present disclosure will now be explained in further detail by way of example only with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an application scenario of the optical path system involved in the present disclosure.

FIG. 2 is a structural block diagram showing an optical path system involved in the present disclosure.

FIG. 3 is a schematic diagram showing the overall optical path of the optical path system involved in the present disclosure.

FIG. 4 is a schematic diagram illustrating an illumination light path involved in the present disclosure.

FIG. 5 is a schematic diagram showing a turntable related to the present disclosure.

FIG. 6 is a schematic diagram illustrating a measurement optical path involved in the present disclosure.

FIG. 7 is a schematic diagram illustrating the confocal principle involved in the present disclosure.

FIG. 8 is a schematic diagram showing a modified example of the total optical path of the optical path system according to the present disclosure.

Detailed ways

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same reference numerals are given to the same components, and repeated descriptions are omitted. In addition, the drawings are only schematic diagrams, and the ratio of dimensions between components, the shape of components, and the like may be different from the actual ones.

It should be noted that the terms "comprising" and "having" and any variations thereof in the present disclosure, such as a process, method, device, product or equipment that includes or has a series of steps or units, are not necessarily limited to those clearly listed. instead, may include or have other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In addition, subheadings and the like involved in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, but are merely used as a reminder for reading. Such subtitles can neither be understood as used to divide the content of the article, nor should the content under the subtitle be limited to the scope of the subtitle.

The present disclosure relates to an optical path system of a microscope, which can be used to measure an object to be measured to reconstruct the three-dimensional shape of the object to be measured. For example, the three-dimensional shape of the object to be tested can be reconstructed by measuring the height information of each area to be tested of the object to be tested. Through the optical path system of the microscope involved in the present disclosure, the measurement accuracy when measuring the object to be measured can be improved.

The optical path system of the microscope involved in this embodiment may be referred to simply as an optical path system, or may also be referred to as an optical path structure.

Hereinafter, the optical path system according to this embodiment will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an application scenario of an optical path system 10 involved in the present disclosure.

In this embodiment, the optical system 10 can be applied in the microscope 1 for reconstructing the three-dimensional shape of the object 2 to be tested. In some examples, the microscope 1 may be a confocal microscope 1 as shown in FIG. 1 .

In some examples, the microscope 1 may include a carrying platform 20 and a measurement host 30 (see FIG. 1 ). Wherein, the carrying platform 20 can be used to carry the object under test 2 . In some examples, the carrier platform 20 can move in two dimensions or in three dimensions. The measurement host 30 can be used to measure the object 2 to obtain measurement information of the object 2 to reconstruct the three-dimensional shape of the object 2 .

In some examples, the object 2 to be measured can be measured based on the optical system 10 disposed on the measurement host 30 . Thus, the three-dimensional shape of the object 2 to be tested can be reconstructed.

In some examples, analyte 2 may be referred to as a sample. Samples can be ultra-precision devices such as semiconductors, 3C electronic glass screens, micro-nano materials, auto parts, or MEMS devices. In some examples, the samples may be devices used in aerospace and other fields. In other examples, the sample may be tissue or cell slices in the biological field.

FIG. 2 is a block diagram showing the structure of the optical system 10 involved in the present disclosure.

In some examples, the optical system 10 involved in this embodiment may include an illumination module 100 , a scanning module 300 , and an imaging module 400 (see FIG. 2 ). Among them, the illumination module 100 can be used to provide the illumination beam L1 for the optical system 10, the scanning module 300 can be used to realize the complete measurement of the object 2 to be measured, and the imaging module 400 can be used to receive the reflected light beam L1' reflected by the object 2 . Thus, the measurement information of the object under test 2 can be obtained based on the received reflected light beam L1 ′.

During the propagation of the illuminating light beam L1 , stray light beams will be generated. The stray light beams are light beams irrelevant to the imaging of the object under test 2 , and the stray light beams will affect the imaging quality of the object under test 2 . In some examples, the optical system 10 may include an auxiliary light absorption module 500, and by setting the auxiliary light absorption module 500 outside the imaging module 400 to absorb stray light beams to weaken the stray light beams in the optical system 10 and reduce the stray light beams to the object under test 2 Imaging effects, improving image quality (details described later). In some examples, a unit for blocking stray light beams can also be provided in the imaging module 400 so that the stray light beams cannot enter the imaging module 400 so as to reduce the impact of stray light beams on the imaging of the object to be measured 2 and improve the imaging quality (more on this later). describe).

FIG. 3 is a schematic diagram showing the overall optical path of the optical path system 10 involved in the present disclosure.

Referring to FIG. 3 , the illuminating beam L1 is emitted by the illuminating module 100 and reaches the spectroscopic module 200. The illuminating beam L1 can pass through the spectroscopic module 200 and irradiate the object 2 through the scanning module 300. The object 2 reflects the illuminating beam L1 to form The reflected light beam L1', the reflected light beam L1' reaches the spectroscopic module 200 via the scanning module 300, and is reflected by the spectroscopic module 200 to the imaging module 400, and the imaging module 400 receives the reflected light beam L1' to obtain the surface information of the object under test 2.

FIG. 4 is a schematic diagram illustrating an illumination light path involved in the present disclosure.

Referring to FIG. 4 , in this embodiment, the illumination light path may include an illumination module 100 , a light splitting module 200 , and a scanning module 300 . In some examples, the lighting module 100 may include a light source 110 and a first polarizing unit 120 (see FIG. 4 ). Wherein, the light source 110 can be used to emit the illumination light beam L1. The first polarization unit 120 can convert the polarization state of the illumination light beam L1 from natural light to linearly polarized light.

In some examples, the light source 110 may be a white LED, and the illumination light beam L1 emitted by the light source 110 may be white light. In some examples, the wavelength of the illumination light beam L1 may be 400nm-700nm. For example, the wavelength of the illumination light beam L1 may be 400 nm, 450 nm, 500 nm, 550 nm, 6000 nm, 650 nm or 700 nm.

In some examples, the first polarizing unit 120 may be a polarizing plate.

In this embodiment, the lighting module 100 may further include a first reflection unit 130 (see FIG. 4 ). The first reflection unit 130 may be disposed on a side of the first polarization unit 120 away from the light source 110 . In other words, the first polarizing unit 120 may be disposed between the light source 110 and the first reflecting unit 130 . In this case, the illumination light beam L1 emitted by the light source 110 can pass through the first polarizing unit 120 and reach the first reflecting unit 130 to be reflected by the first reflecting unit 130 to the spectroscopic module 200 (described later), thereby, The space occupation of the optical path system 10 can be reduced to improve the integration of the optical path system 10 .

In some examples, the lighting module 100 may further include a first lens unit 140 disposed between the light source 110 and the first reflection unit 130 (see FIG. 4 ). The first lens unit 140 may be configured to collimate the illumination light beam L1. Thus, the illumination light beam L1 can become parallel light after passing through the first lens unit 140 .

In some examples, the first lens unit 140 may be a collimating lens. For example, it may be a glass aspheric positive power lens. In some examples, the aspheric lens can effectively improve the efficiency of light energy utilization. But this embodiment is not limited thereto, and in some other examples, the first lens unit 140 may also be an aspherical lens.

In this embodiment, the lighting module 100 may further include a second lens unit 150 disposed between the light source 110 and the first reflection unit 130 . The second lens unit 150 can be configured to adjust the collimated illumination light beam L1 so that the image 110 ′ of the light source is located at the rear focal plane of the microscope objective lens 330 . In this case, the light source 110 can be regarded as being located at the entrance pupil of the microscope objective lens 330 , so that the illumination beam L1 can evenly irradiate the surface of the object 2 to be measured.

As mentioned above, the lighting module 100 may include the first reflective unit 130 . In some examples, the first reflection unit 130 can be used to reflect the illumination beam L1 to the light splitting module 200 . In some examples, the illumination module 100 may not include the first reflection unit 130 , and the illumination beam L1 may directly reach the beam splitting module 200 via the first lens unit 140 , the second lens unit 150 , and the first polarization unit 120 in sequence.

In some examples, the spectroscopic module 200 can be configured to reflect part of the illumination beam to the inner wall of the microscope 1 and transmit part of the illumination beam to the scanning module 300 . Wherein, the illuminating light beam reflected to the inner wall of the microscope 1 has no contribution to the measurement of the object under test 2 , and in addition, it will bring certain negative effects to the optical path system 10 . For the convenience of description, the illumination beam reflected by the spectroscopic module 200 to the inner wall of the microscope 1 is referred to as the first stray beam L11, and the illuminating beam L1 transmitted by the spectroscopic module 200 to the scanning module 300 is still referred to as the illumination beam L1.

In some examples, the spectroscopic module 200 may be disposed between the illuminating module 100 and the scanning module 300 , and the illuminating light beam L1 reaches the scanning module 300 after passing through the spectroscopic module 200 . In other words, the scanning module 300 may be configured to receive the illumination beam L1 passing through the spectroscopic module 200 .

FIG. 5 is a schematic diagram showing a turntable 310 involved in the present disclosure.

Referring to FIG. 4 , in some examples, the scanning module 300 may include a turntable 310 having a light transmission hole 311 , a second polarization unit 320 , and a microscope objective lens 330 . The illuminating light beam L1 can reach the object under test 2 via the turntable 310 , the second polarizing unit 320 , and the microscope objective lens 330 in sequence, and is reflected by the object under test 2 to form a reflected light beam L1 ′. In other words, the turntable 310 having the light-transmitting hole 311 , the second polarizing unit 320 , and the microscope objective lens 330 may be sequentially arranged along the propagation direction of the illumination beam L1 .

Referring to FIG. 5 , in some examples, a plurality of light-transmitting holes 311 may be evenly arranged on the turntable 310 in an Archimedean spiral manner. When the illumination beam L1 reaches the turntable 310 , part of it can pass through the turntable 310 through the light hole 311 to reach the second polarizing unit 320 (hereinafter referred to as the illumination beam L1 ), and part of it is reflected by the turntable 310 to form the second stray light beam L12 .

In some examples, the position of the light-transmitting hole 311 can be changed by rotating the turntable 310 so that the illumination beam L1 reaches each region to be measured of the object to be measured 2 . Thus, a complete scan of the object to be tested 2 can be realized.

In some examples, the turntable 310 having light-transmitting holes 311 may be a Nipkow turntable. In some examples, a turntable lens 312 for observing the object under test 2 may be arranged on the turntable 310 . In this case, through the turntable lens 312 arranged on the turntable 310 , the object 2 and the region to be measured of the object 2 can be quickly found.

In some examples, the turntable 310 may be disposed on the scanning module 300 parallel to the carrying platform 20 . Thus, the illumination light beam L1 can enter the scanning module 300 through the light transmission hole 311 .

Referring to FIG. 4 , in some examples, the central axis of the turntable 310 and the preset direction D1 may have a first preset angle greater than 0°. In other words, the turntable 310 may be inclined. Preferably, the inclination direction of the turntable 310 may be as shown in FIG. 4 . In this case, the illumination beam L1 can also enter the scanning module 300 through the light hole 311, and when part of the illumination beam is reflected by the turntable 310 to form the second stray beam L12, the propagation direction of the second stray beam L12 can be Propagating away from the imaging module 400 can reduce the possibility that the second stray light beam L12 enters the imaging module 400 to affect the imaging of the object under test 2 .

In some examples, the preset direction D1 may be a direction perpendicular to the carrying platform 20 .

In some examples, the second polarization unit 320 may be a 1/4 wave plate. In this case, the illumination beam L1 and the reflected beam L1' pass through the 1/4 wave plate successively, which can rotate the reflected beam L1' emitted from the scanning module 300 by 90° relative to the polarization direction of the illumination beam L1, so that the object under test 2. The reflected light beam L1' from the surface passes through the third polarizing unit 420 and is received by the sensing unit 410 (described later). In some examples, the second polarizing unit 320 may be arranged at an angle of 45° to the preset direction D1.

In some examples, the scanning module 300 may further include a tube lens 340 disposed between the turntable 310 and the microscope objective lens 330 . The tube lens 340 can be configured to adjust the illumination beam L1 so that the image 110 ′ of the light source is located at the entrance pupil of the microscope objective 330 , that is, the back focal plane (or back focal plane) of the microscope objective 330 . Thus, the illumination light beam L1 can evenly irradiate the surface of the object 2 to be measured.

In some examples, tube lens 340 may be a single lens. In other examples, the tube lens 340 may be composed of multiple lenses.

In some examples, microscope objective 330 may be an infinity microscope objective 330 . In this case, if the area to be measured of the object 2 is located at the focal plane of the microscopic objective lens 330 , the reflected light beam L1 ′ reflected by the area to be measured can become parallel light after exiting the microscopic objective lens 330 .

FIG. 6 is a schematic diagram illustrating a measurement optical path involved in the present disclosure. FIG. 7 is a schematic diagram illustrating the confocal principle involved in the present disclosure.

Referring to FIG. 6 , in some examples, the measurement optical path may include a scanning module 300 , a spectroscopic module 200 , and an imaging module 400 . The scanning module 300 can be configured to receive the reflected beam L1 ′ from the object 2 and output the reflected beam L1 ′ to the spectroscopic module 200 , and then the spectroscopic module 200 can reflect the reflected beam L1 ′ to the imaging module 400 .

Referring to Fig. 7, taking the objective lens 1000 as an example, in the principle of confocal scanning, only the reflected beam reflected by the area to be measured located on the focal plane S of the objective lens 1000 can be focused on the pinhole 2000, while the area to be measured located on the non-focal plane S Reflected reflected beams are blocked. In other words, after the confocal action of the scanning module 300 , the reflected light beam reflected by the non-focus plane can be filtered. Thus, the imaging of the object 2 to be tested can be made clearer.

In the optical path shown in FIG. 7 , if the area to be measured of the object to be measured 2 needs to be adjusted to be located at the focal plane of the objective lens, the pinhole and the objective lens can be regarded as moving together as a whole.

Compared with the traditional confocal structure shown in FIG. 7 , the present disclosure introduces a tube lens 340 in the scanning module 300. In the measurement optical path, the tube lens 340 can also be configured to receive the parallel light emitted by the microscope objective lens 330 ( That is, the reflected light beam L1 ′) reflected from the focal plane of the microscope objective lens 330 is focused and imaged to the light transmission hole 311 of the turntable 310 . If you want to adjust the area to be measured of the object to be measured 2 so that it is located at the focal plane of the microscopic objective 330, you only need to adjust the position of the microscopic objective 330 in the preset direction, and the weight of the microscopic objective 330 Therefore, the measurement optical path can be adjusted more flexibly so that the region to be measured of the object to be measured 2 is located at the focal plane of the microscope objective lens 330 .

In this embodiment, the sleeve lens 340 can also be configured to adjust the reflected light beam L1 ′ so that the reflected light beam L1 ′ is focused on the light transmission hole 311 . In this case, the reflected light beam L1′ reflected by the area to be measured on the focal plane can exit from the scanning module 300 and reach the imaging module 400, thereby enhancing the signal-to-noise ratio of the imaging image to improve the measurement of the object to be measured 2 precision.

In some examples, the optical system 10 may further include a driving module 600 (see FIG. 2 ) having a first driving mechanism. Wherein, the first driving mechanism can be configured to drive the microscope objective lens 330 to move in a preset direction D1 so that the area to be measured of the object 2 is located at the focal plane of the microscope objective lens 330 . In this case, by adjusting the position of the microscopic objective lens 330 in the preset direction, the area to be measured of the object to be measured 2 can be located at the focal plane of the microscopic objective lens 330, thus, the reflected light beam L1 reflected by the area to be measured ′ can be focused on the light transmission hole 311.

In some examples, the optical system 10 may further include a position recording module 700 (see FIG. 2 ). The position recording module 700 can be used to obtain and record the position information of the microscope objective lens 330 . The height information of the object under test 2 can be obtained based on the position information of the microscopic objective lens 330 and the light intensity information of the reflected light beam L1 ′.

In some examples, the driving module 600 may further include a second driving mechanism for driving the turntable 310 to move. In some examples, the second driving mechanism can drive the turntable 310 to rotate around the central axis of the turntable 310 . In this case, by driving the turntable 310 to move, the illuminating light beam L1 can reach each area of the object 2 to be measured, so that complete measurement information of the object 2 can be obtained. In some examples, a second drive mechanism may be provided on the turntable 310 .

As mentioned above, the scanning module 300 can receive the reflected light beam L1 ′ from the object 2 and output the reflected light beam L1 ′ to the spectroscopic module 200 . In some examples, the spectroscopic module 200 can also be configured to receive the reflected light beam L1 ′ from the scanning module 300 and reflect the reflected light beam L1 ′ to the imaging module 400 . Thus, the imaging module 400 can receive the reflected light beam L1' from the object under test 2, and obtain light intensity information of the reflected light beam L1'.

In some examples, the imaging module 400 may include a sensing unit 410 and a third polarizing unit 420 disposed between the sensing unit 410 and the spectroscopic module 200 (see FIG. 6 ). The reflected light beam L1 ′ can reach the sensing unit 410 via the third polarizing unit 420 after being reflected by the spectroscopic module 200 . In other words, the sensing unit 410 may be configured to receive the reflected light beam L1 ′ transmitted through the third polarizing unit 420 .

In some examples, sensing unit 410 may be a CCD or CMOS camera. The third polarizing unit 420 may be a polarizing plate having a different polarization direction from that of the first polarizing unit 120 . Thus, the illumination light beam L1 transmitted by the first polarizing unit 120 may be absorbed by the third polarizing unit 420 but not transmitted by the third polarizing unit 420 .

In some examples, preferably, the polarization direction of the first polarization unit 120 may be orthogonal to the polarization direction of the third polarization unit 420 . In this case, even if the illumination light beam L1 (second stray light beam L12) reflected by the turntable 310 is reflected to the imaging module 400 via the spectroscopic module 200, the second stray light beam L12 cannot pass through the third polarizing unit 420 and further Reaching the sensing unit 410, in other words, the setting of the third polarizing unit 420 can reduce the possibility that the sensing unit 410 receives the reflected light beam (that is, stray light) that is not reflected by the object to be measured 2, thereby improving the optical path system 10. The measurement accuracy of DUT 2 can be reconstructed more accurately.

In this embodiment, since the illumination light beam L1 passing through the scanning module 300 and the reflected light beam L1′ which reaches the object 2 and is reflected by the object 2 pass through the second polarizing unit 320 successively, the scanning module 300 The polarization direction of the outgoing reflected light beam L1' can be rotated by 90°. In this case, the reflected light beam L1' can pass through the third polarization unit 420 and reach the sensing unit 410, and the sensing unit 410 can receive the reflected light beam L1' reflected from the object 2, thereby reducing the The noise interferes with the target signal, thereby improving the signal-to-noise ratio of the target signal, and improving the imaging quality of the reflected light beam L1 ′ after reaching the sensing unit 410 .

In some other examples, the polarization directions of the first polarization unit 120 and the third polarization unit 420 may not be orthogonal, for example, the polarization directions of the two may have any angle θ that is not zero. At this time, if the illumination beam L1 passes through After passing through the second polarization unit 320, the polarization direction of the illumination light beam L1 can be changed by half of θ. When passing through the second polarizing unit 320 back and forth, the polarization direction of the illumination light beam L1 may change by θ. In some examples, the imaging module 400 may further include a third lens unit 430 disposed between the sensing unit 410 and the third polarizing unit 420 . In some examples, the third lens unit 430 may be a relay lens. The third lens unit 430 can be used to converge the reflected light beam L1 ′ to the sensing unit 410 .

FIG. 8 is a schematic diagram illustrating a modified example of the total optical path of the optical path system 10 according to the present disclosure.

In this embodiment, the optical system 10 may further include an auxiliary light absorption module 500 (see FIG. 8 ) for absorbing the first stray light beam L11. In some examples, the auxiliary light absorption module 500 may be disposed on the inner wall of the microscope 1 , and when the first stray light beam L11 is reflected to the inner wall, it will be absorbed by the auxiliary light absorption module 500 (details will be described later). In this case, the first stray light beam L11 in the optical system 10 can be reduced so as to improve the imaging quality of the object under test 2 subsequently.

As mentioned above, the illuminating light beam L1 will generate the first stray light beam L11 (the illuminating light beam reflected by the spectroscopic module 200 to the inner wall of the microscope 1 ) during its propagation. The present disclosure also provides an optical path system 10 with an auxiliary light absorption module 500, which can absorb the first stray light beam L11 based on the above-mentioned auxiliary light absorption module 500 to reduce the first stray light beam L11 in the optical path system 10 to improve the quality of the object under test. 2 image quality.

Referring to FIG. 8 , in some examples, the auxiliary light-absorbing module 500 may include a fourth polarizing unit 510 , a second reflecting unit 520 , and a light-absorbing paper 530 . Wherein, the fourth polarizing unit 510 may be disposed on the inner wall in a manner of being inclined at a second preset angle relative to the optical axis. In some examples, tilting relative to the optical axis may refer to tilting relative to the optical axis of the first stray light beam L11. In some examples, the second preset angle may not be zero. In other words, the fourth polarizing unit 510 may be inclined relative to the preset direction D1. In some examples, the fourth polarizing unit 510 may be configured to absorb the first stray light beam L11 from the light splitting module 200 . In some examples, the polarization direction of the fourth polarization unit 510 may be the same as that of the third polarization unit 420 . Thus, the fourth polarizing unit 510 can absorb the first stray light beam L11 to attenuate the stray light beam in the optical system 10 .

In some examples, the fourth polarizing unit 510 can also be configured to reflect the first stray beam L11 to the second reflecting unit 520, and the second reflecting unit 520 can be configured to receive the first stray beam from the fourth polarizing unit 510 L11 and reflect the first stray light beam L11 to the light-absorbing paper 530 . In this case, if the first stray light beam L11 is not completely absorbed by the fourth polarization unit 510, the fourth polarization unit 510 can reflect the first stray light beam L11 to the second reflection unit 520, and then the second reflection unit 520 reflects the first stray light beam L11 to the light-absorbing paper 530 to absorb the remaining first stray light beam L11 , thereby further reducing the stray light beam in the optical path system 10 .

In some examples, the second reflection unit 520 may be a concave mirror. In some examples, the side of the second reflection unit 520 receiving the first stray light beam L11 may be uneven. In this case, after the first stray light beam L11 reaches the second reflection unit 520, it will be reflected multiple times by the second reflection unit 520 to weaken the first stray light beam L11, thus, the first stray light beam L11 can be reduced. The energy of L11.

In some examples, light-absorbing paper 530 may be disposed on the inner wall. In some examples, light absorbing paper 530 may be located outside the field of view of sensing unit 410 . In this case, even if the first stray light beam L11 is not completely absorbed, it cannot propagate to the sensing unit 410 and affect the imaging of the object under test 2 .

In this embodiment, the optical system 10 may further include a processing module. The processing module may be configured to obtain height information of the object 2 to be measured based on the light intensity information of the reflected light beam L1 ′ to reconstruct the object 2 . Thus, the three-dimensional shape of the object 2 to be tested can be reconstructed.

In the present disclosure, by setting the turntable 310 obliquely, the illumination beam reflected by the turntable 310 can be propagated away from the imaging module 400 , further, by setting the first polarizing unit 120 in the illumination module 100 , the imaging module 400 A third polarizing unit 420 perpendicular to the polarization direction of the first polarizing unit 120 is provided in the middle, so that the illumination beam reflected by the turntable 310 is blocked and cannot enter the sensing unit 410 . In this case, it is possible to reduce the possibility that the reflected light beam reflected by the non-test object 2 enters the imaging module 400 and is received by the sensing unit 410, thus, the signal-to-noise ratio of the reflected light beam from the test object 2 can be improved to Improving the imaging quality can further improve the reconstruction accuracy of the object to be measured 2 . In addition, the present disclosure also provides an optical system 10 with an auxiliary light absorption module 500, through which the auxiliary light absorption module 500 can weaken the stray light beams generated by the light splitting module 200 in the optical system 10 to further improve the imaging of the object under test 2 quality.

To sum up, according to the present disclosure, it is possible to provide an optical path system 10 capable of reducing stray light in the optical path so as to improve the measurement accuracy of the object 2 to be measured and thus the reconstruction accuracy of the object 2 to be detected.

Although the present disclosure has been described in detail with reference to the drawings and examples, it should be understood that the above description does not limit the present disclosure in any form. Those skilled in the art can make modifications and changes to the present disclosure as needed without departing from the true spirit and scope of the present disclosure, and these modifications and changes all fall within the scope of the present disclosure.

Claims (10)

1. An optical path system of a microscope, characterized in that, the optical path system includes an illumination module, a spectroscopic module, a scanning module, and an imaging module, and the illumination module includes a first polarization unit and a light source for emitting an illumination beam; The spectroscopic module is arranged between the illumination module and the scanning module and is configured to receive the reflected beam from the scanning module and reflect the reflected beam to the imaging module; the scanning module is configured to receive The illumination beam of the spectroscopic module is emitted to the object under test and the reflected beam is received from the object to be measured and the reflected beam is emitted to the spectroscopic module. A turntable with a light transmission hole, a second polarization unit, and a microscope objective lens; the imaging module includes a sensing unit, a third polarization unit arranged between the sensing unit and the light splitting module, the The sensing unit is configured to receive the reflected light beam transmitted through the third polarization unit, the polarization direction of the first polarization unit is different from the polarization direction of the third polarization unit. 2. The optical path system according to claim 1, wherein the illumination module further comprises a first reflection unit for reflecting the illumination beam to the light splitting module, and the first polarization unit is arranged on the light source and the first reflection unit. 3. The optical path system according to claim 2, wherein the lighting module further comprises a first lens unit and a second lens unit disposed between the light source and the first reflection unit, the first lens unit A lens unit is configured to collimate the illumination beam, and the second lens unit is configured to adjust the collimated illumination beam so that the position of the image of the light source is located at the microscope objective lens. 4. The optical system according to claim 1, wherein the polarization direction of the first polarization unit is perpendicular to the polarization direction of the third polarization unit. 5. The optical system according to claim 1, wherein the second polarization unit is a 1/4 wave plate. 6. The optical system according to claim 1, further comprising a driving module having a first driving mechanism configured to drive the microscope objective lens to move in a preset direction so that the The area to be measured of the object to be measured is located at the focal plane of the microscope objective lens. 7. The optical system according to claim 6, wherein the central axis of the turntable and the preset direction have a first preset angle greater than 0°. 8. The optical system according to claim 1, wherein the scanning module further comprises a tube lens disposed between the turntable and the microscope objective lens, the tube lens is configured to adjust the illumination beam The image of the light source is located on the rear focal plane of the microscope objective lens, and the reflected light beam is adjusted so that the reflected light beam is focused on the light transmission hole. 9. The optical system according to claim 1, further comprising an auxiliary light absorption module for absorbing the first stray light beam, the first stray light beam is reflected to the microscope by the light splitting module in the illumination light beam the light beam on the inner wall of the inner wall, the auxiliary light-absorbing module includes a fourth polarizing unit arranged on the inner wall in a manner of inclining a second preset angle relative to the optical axis, a second reflecting unit, and a second reflecting unit arranged on the inner wall and located at the light-absorbing paper outside the field of view of the sensing unit, the fourth polarizing unit is configured to absorb the first stray beam from the spectroscopic module and reflect the first stray beam to the second reflecting unit, the The second reflecting unit is configured to receive the first stray beam from the fourth polarizing unit and reflect the first stray beam to the light-absorbing paper. 10. The optical system according to claim 9, wherein the polarization direction of the fourth polarization unit is the same as that of the third polarization unit.

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